Fig 5.
Infectious virus present in aerosols exhaled from influenza virus-infected ferrets. Aerosols were collected from ferrets inoculated with 102.7 to 107 PFU of PN99 (A), SI06 (B), MX09 (C), TH04 (D), or BD11 (E) virus IN (green) or by AR inhalation (orange) during normal breathing or sneezing using a viable cascade impactor (n = 4 [SI06, MX09, and BD11], 5 [PN99], and 6 [TH04]). Virus titers collected on impactor plates on alternating days after inoculation were determined by plaque assay without dilution, and total PFU is shown for each ferret on the left y axis. Viral RNA levels in the same samples from combined IN and AR experiments were estimated by real-time RT-PCR and are shown as lines on the right y axis.